High amplitude tremor stabilization by a handheld tool

ABSTRACT

Systems and methods for tracking unintentional high amplitude muscle movements of a user and stabilizing a handheld tool are described. The method may include detecting motion of a housing of the handheld tool when manipulated by a user while the user is performing a task with a user-assistive device attached to an attachment arm of the handheld tool, and storing the detected motion in a memory of the handheld tool as motion data. Furthermore, the method may include controlling a first motion generating mechanism and a second motion generating mechanism by generating a first motion signal and a second motion signal that respectively drive the first motion generating mechanism in a first degree of freedom and the second motion generating mechanism in a second degree of freedom to stabilize motion of the user-assistive device attached to the attachment arm of the handheld tool.

CROSS-REFERENCE TO RELATED APPLICATION

The present patent application is a divisional of U.S. application Ser.No. 15/210,267, filed on Jul. 14, 2016, the contents of which are herebyincorporated by reference.

TECHNICAL FIELD

This disclosure relates generally to unintentional muscle movements, andin particular but not exclusively, relates to tracking unintentionalmuscle movements of a user and stabilizing a handheld tool while it isbeing used by the user.

BACKGROUND INFORMATION

Movement disorders are often caused by chronic neurodegenerativediseases such as Parkinson's Disease (“PD”) and Essential Tremor (“ET”).Both of these conditions are currently incurable and cause unintentionalmuscle movements or human tremors—uncontrollable rhythmic oscillatorymovements of the human body. In many cases human tremors can be severeenough to cause a significant degradation in quality of life,interfering with daily activities/tasks such as eating, drinking, orwriting.

Currently, persons with chronic neurodegenerative diseases are typicallymedicated with drugs that vary in effectiveness. The alternative topharmacological treatment is brain surgery, such as deep brainstimulation (DBS) surgery. Similar to pharmacological treatments, DBSsurgery varies in its effectiveness while being invasive and dangerous.Both forms of treatment are therefore non-optimal for treating personswith chronic neurodegenerative diseases, especially with respect toperforming daily activities.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the invention aredescribed with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified. The drawings are not necessarily to scale,emphasis instead being placed upon illustrating the principles beingdescribed.

FIG. 1A is a perspective view illustration of a handheld tool thattracks unintentional muscle movements and performs high amplitude motionstabilization, in accordance with an embodiment of the disclosure.

FIG. 1B is a perspective view illustration of motion generatingmechanisms of a handheld tool that tracks unintentional muscle movementsand performs high amplitude motion stabilization, in accordance with anembodiment of the disclosure.

FIG. 1C is a perspective view illustration of a handheld tool thattracks unintentional muscle movements and performs high amplitude motionstabilization with a user-assistive device detached from the handheldtool, in accordance with an embodiment of the disclosure.

FIG. 2 is a perspective view illustration of a sealed handheld tool thattracks unintentional high amplitude muscle movements and performs motionstabilization, in accordance with an embodiment of the disclosure.

FIG. 3 is a functional block diagram illustrating a tremor trackingmodule, in accordance with an embodiment of the disclosure.

FIG. 4 is a flow chart illustrating a process for tracking unintentionalmuscle movements of a user while using a handheld tool and performinghigh amplitude motion stabilization by the handheld tool, in accordancewith an embodiment of the disclosure.

DETAILED DESCRIPTION

Embodiments of an apparatus, system and process for trackingunintentional high amplitude muscle movements of a user while using ahandheld tool and stabilizing the handheld tool while the handheld toolis used to perform an ordinary activity, are described herein. In thefollowing description numerous specific details are set forth to providea thorough understanding of the embodiments. One skilled in the relevantart will recognize, however, that the techniques described herein can bepracticed without one or more of the specific details, or with othermethods, components, materials, etc. In other instances, well-knownstructures, materials, or operations are not shown or described indetail to avoid obscuring certain aspects.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, theappearances of the phrases “in one embodiment” or “in an embodiment” invarious places throughout this specification are not necessarily allreferring to the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments.

FIG. 1A illustrates a handheld tool 100 that tracks unintentional highamplitude muscle movements and performs motion stabilization, inaccordance with an embodiment of the disclosure. Handheld tool 100 iscapable of detecting and compensating for unintentional high amplitudemuscle movement (e.g. tremors). In one embodiment, the muscle movementsare high amplitude when they occur in a range of approximately 1-2centimeters about a central point of the handheld tool, althoughunintentional high amplitude muscle movements may be as large as 8-10centimeters about a central point of the handheld tool. In theembodiments discussed herein, the handheld tool 100 tracks theseunintentional high amplitude muscle movements, and stabilizes (i.e.,centers) a position of implement 106 in spite of the unintentional highamplitude muscle movements while implement is being used by a user.

Accordingly, the illustrated embodiment of handheld tool 100 includes atremor tracking module 120 for measuring and tracking user tremors, aswell as two or more sensors (e.g., sensor 122 and 124) for providingsignals to the tremor tracking module 120 for compensating for thosesame tremors, as discussed herein. These subsystems may have distinctcomponents, or share some components such as power systems, memory, andmay even share one or more sensors.

Handheld tool 100 includes a housing 106, which functions as a handleenabling a user to hold handheld tool 100. Handheld tool 100 alsoincludes an attachment arm 104 coupled to the housing 106 via motiongenerating mechanisms, as discussed in greater detail below. Attachmentarm 104 is configured to accept an implement 102 (e.g., a user-assistivedevice, such as a spoon in the illustrated embodiment) to its end distalfrom housing 106. In one embodiment, attachment arm 104 is integratedwith a specific type of implement 102 (e.g., the spoon as illustrated).In other embodiments, attachment arm 104 can receive a variety ofdifferent implements 102 in a variety of ways including but not limitedto a friction, snap, magnet, screw, or other form of locking mechanism.FIG. 1C is a perspective view of one embodiment of the implement 102detached from the attachment arm 104 of handheld tool 100, such that aplurality of different implements can be selectively attached toattachment arm 104.

Handheld tool 100 includes tremor tracking module (“TTM”) 120 formeasuring and tracking tremors, such as unintentional high amplitudemuscle movements of a user, as well as for controlling stabilizationperformed by the handheld tool using a first motion generating mechanism(e.g., the first actuator 108, first gear reduction unit 110, and firstgearing unit 112) and a second motion generating mechanism (e.g., thesecond actuator 130, second gear reduction unit 132, and second gearingunit 134), discussed in greater detail below. In embodiments, theattachment arm 104 is coupled with the housing 106 via the coupling ofthe first motion generating mechanism with the second motion generatingmechanism. Furthermore, one or more components of TTM 120 are rigidlyattached to housing 106 to measure and track tremors of the handle thatthe user holds. FIG. 1A illustrates TTM 120 as a single component withinhousing 106; however, in other embodiments, TTM 120 includes severalfunctional items that may assume a variety of different form factors andmay further be spread throughout housing 106, such as within attachmentarm 104.

The illustrated embodiment of handheld tool 100 further includes atleast two motion sensors (e.g., a first motion sensor 122 placed alongor within body and a second motion sensor 124 placed along or withinattachment arm 104). The motion sensors 122 and 124 respectively measuremovements of housing 106 and attachment arm 104, to enable TTM 120 todetermine movements of housing 106 and attachment arm 104 relative toone another. The sensor 122 sends motion signals back to TTM 120 so thatTTM 120 can determine, in real time or near real time, direction, speed,and magnitude of unintentional high amplitude muscle movements of a userusing handheld tool 100. These measured movements are provided to TTM120 to enable TTM 120 to provide motion signals that drive the first andsecond motion generating mechanisms to stabilize the implement 102despite the user's unintentional high amplitude muscle movements. In oneembodiment, the motion sensors 122 and 124 are sensors including but notlimited to one or more of an accelerometer, gyroscope, or combination ofthe two. In another embodiment, each of motion sensor 122 and 124 is ainertial measuring unit.

Handheld tool 100 further includes a portable power source 140 to powerthe TTM 120, actuator 108, and actuator 130. The portable power source140 can include one or more rechargeable batteries. In embodiments, therechargeable batteries of portable power source 140 may be recharged viacharging interface 142 to a charging power source, where charginginterface 142 couples portable power source 140 to the charging powersource via an indicative, wired, or other form of connection.Furthermore, power source 140 may utilize other options including butnot limited to a solar panel, primary batteries, etc.

In one embodiment, the first motion sensor 122 and second motion sensor124 are inertial motion sensors respectively distributed in housing 106and attachment arm 104. In another embodiment, the second motion sensor124 can be an accelerometer with or without a gyroscope. In oneembodiment, the first motion sensor 122 is responsible for measuringmovements of the housing 106 and the second motion sensor 124 isresponsible for measuring movements of the attachment arm 104. The firstand second motion sensors 122 and 124 provide motion signals, indicativeof the measured movements, to TTM 120 for determining the motion of thehousing 106 as well as the relative motions of the housing 106 and theattachment arm 104. In embodiments, one or more of the components fortracking tremor motions and/or performing motion stabilization may beomitted and/or positions of sensors changed while still implementing thetremor tracking and motion stabilization functionality disclosed herein.As examples, rotary encoders, potentiometers, or other position trackingdevices placed on the joints of movement of the handheld tool 100, and asingle motion sensor can be employed either in the tip (e.g., attachmentarm 104 or implement 102) or housing 106. In these embodiments, thecombination of sensors and placement on handheld tool 100 enable TTM 120to infer (through device kinematics) where attachment arm 104 andhousing 106 are, and their positions relative to each other, for tremortracking and motion compensation purposes.

The first motion sensor 122 and second motion sensor 124 detectunintentional muscle movements and measure signals related to theseunintentional muscle movements that are created when a user adverselyaffects motion of implement 102 (e.g., as a result of unintentional highamplitude muscle movements). These sensors also detect the motion of thestabilized output relative to the housing 106. In one embodiment, thefirst motion sensor 122 detects movements of the housing 106, althoughsensor 124 could also be used for detecting movements of the housing106. Furthermore, the combined measurements of the sensors 122 and 124enable movements of the housing 106 and implement 102 relative to oneanother to also be detected. TTM 120 sends voltage commands in responseto the detected motions to at least one of actuator 108 and actuator130. The voltage commands are chosen by TTM 120 to generate acomplementary motion to the detected motions of housing 106. In oneembodiment, the complementary motion is a positioning of attachment arm104 upon jointly driving actuator 108 and actuator 130 to stabilizeimplement 102 (e.g., maintain implement 102 in a centered positionrelative to the user's tremors or unintentional muscle movementseffecting motion of the handle 106). The voltage commands drive one ormore of actuator 108 and actuator 130 to generate motion of theattachment arm 104 and therefore the implement 102 in a directionopposite to the detected user motions. Furthermore, the voltage commandsfurther drive one or more of actuator 108 and actuator 130 to generate amotion of equal magnitude of the detected user motion. The voltagecommands of TTM 120 therefore control motion of the implement 102 byjointly driving the motion generating mechanisms to cancel out theuser's unintentional high amplitude motion thereby stabilizing theimplement 102 relative to motion of the housing 106 by a user.

In one embodiment, the handheld tool 100 includes a first motiongenerating mechanism having the first actuator 108, first gear reductionunit 110, and first gearing unit 112. In response to a first set ofvoltage commands of the TTM 120, the first actuator 108 drives the firstgearing unit 112 through the first gear reduction unit 112 to move theattachment arm 104 and the attached implement 102 on pivot 150 in afirst degree of freedom 152 relative to the housing 106. Similarly, inresponse to a second set of voltage commands of the TTM 120, the secondactuator 130 drives the second gearing unit 134 through the second gearreduction unit 132 to move the attachment arm 104 and the attachedimplement 102 on pivot 160 in a second degree of freedom 162 relative tothe housing 106. The first degree of freedom and the second degree offreedom are different, and in one embodiment, the first and seconddegrees of freedom are perpendicular to one another (e.g., 90 degreesdifferent from one another). In embodiments, the first and/or secondmotion generating mechanisms employ gearing units that translate motionto orthogonal directions relative to the motions generated by theirrespective actuators. Such a translation of motion of the actuators toan orthogonal direction can be achieved through bevel gearing units,such as those illustrated in FIGS. 1A-1C. Other types of gearing orcombinations of types of gearing, such as work gearing units, a workgearing unit and a bevel gearing unit, etc., capable of translating theactuators' 108 and 130 motions to orthogonal directions can be employedby the handheld tool 100 consistent with the discussion herein.

FIG. 1B illustrates a zoomed in perspective view of the first and secondmotion generating mechanisms, including the first actuator 108, firstgear reduction unit 110, first gearing unit 112 that moves an attachmentarm in a first degree of freedom through pivot 150, as well as thesecond actuator 130, second gear reduction unit 132, second gearing unit134 that moves the attachment arm in a second degree of freedom throughpivot 160. As noted above, the attachment arm of the handheld tool iscoupled with the housing via the coupling of the first motion generatingmechanism with the second motion generating mechanism, such as by havingpivots 150 and 160 share a common, or connected, structure. Although theillustrated motion generating mechanisms utilize actuators that drivethe movement of the attachment via shell gearing units and pivots, inembodiments, other types of actuators and drive units (e.g., directdrive actuators) could be used in the motion generating mechanismsconsistent with the discussion herein.

Returning to FIG. 1A, in embodiments, the motions of the attachment arm104 and the attached implement 102 in the first and second degrees offreedom enable TTM 120 to stabilize implement 102 in 360 degrees offreedom (e.g., responsive to any pattern and direction of unintentionalmuscle movements of a user). Furthermore, in embodiments, each ofactuators 108 and 130 drive its respective gearing unit 112 and 134 adistance in the range of 2 cm from peak to peak in its respective degreeof freedom, and up to a potential range of 10 cm from peak to peak inits respective degree of freedom. That is, voltage commands from TTM 120that jointly drive a position of attachment arm 104 and the attachedimplement 102 via control of actuators 108 and 130 provide motionstabilization of implement 102 (e.g., centering of implement 102 at asingle point in space) up to a total range of 10 cm about thestabilization point in 360 degrees of freedom. Such a range of motionstabilization, provided in real time as a user uses handheld tool 100,enables the stabilization of implement 102 in a range suitable forcancelling unintentional high amplitude muscle movements of a user.

In embodiments, the first actuator 108 and the second actuator 130 areeach disposed within handheld tool in an orientation parallel to housing106. That is, the first actuator 108 is parallel and in-line with thebody of the housing 106, and the second actuator 130 is parallel andin-line with the body of the body of the attachment arm 104. Forexample, actuators 108 and 130 may be substantially cylindrical inshape, and placement of the actuators within and in line with thehousing 106 and attachment arm 104 ensures that the diameter of theattachment arm and housing can be reduced to a minimum that accommodatesthe components of the handheld tool.

Then, in order to provide movement of the implement 102 in the first andsecond degrees of freedom, the actuators drive their respective gearingunits 112 and 134 to control motions of the attachment arm 104 and theattached implement 102. Furthermore, by orienting the actuators 108 and130 in this direction, a form factor of the housing 108 can be reduced,for example, as compared to the form factor needed when an actuator isperpendicular (or another orientation) relative to a handheld tool'shousing. Beneficially, reducing the form factor of the housing ensuresthe handheld tool 102 more closely resembles a tradition version of thehandheld tool, thereby making the handheld tool easy to use.Additionally, users that use the handheld tool 102 which more closelyresembles a tradition version of the handheld tool are more comfortableusing such a tool, as it is more familiar and does not resemble aspecialized/assistive device.

FIG. 2 is a perspective view illustration of another embodiment, of ahandheld tool. In the embodiment of FIG. 2 , a sealed handheld tool 200that tracks unintentional high amplitude muscle movements and performsmotion stabilization, in accordance with an embodiment of thedisclosure, is illustrated. The sealed handheld tool 200 includes ahousing 206, attachment arm 204, and implement 202 coupled to theattachment arm 204. Furthermore, handheld tool 200 is similar tohandheld tool 100 discussed above, in that it includes a power source,control circuit (e.g., a TTM), a plurality of motion sensors to trackmovements of the handheld tool 200 and attachment arm 204/implement 202,motion generating mechanisms, etc., each configured to perform thefunctions discussed above in FIG. 1A.

In one embodiment, handheld tool 200 is sealed to provide amoisture/debris resistance and/or proofing of the motion generatingmechanism portions of the handheld tool 200. In one embodiment, abarrier, such as a flexible sleeve 260, is fixed to the housing 206 andthe attachment arm 204. In one embodiment, the flexible sleeve 260 maybe a flexible tube constructed of moisture impermeable silicon, plastic,nylon, rubber, etc. Such a flexible sleeve will protect the gearingunits, gear reduction units, and actuators from unwanted moisture and/ordebris that may be encountered during use of the implement (e.g., whilea user is eating with a spoon implement attached to the handheld tool200), as well as from moisture and debris working its way into thehousing 206 and/or attachment arm 204 portions of handheld tool 200.Beneficially, by providing protection of the motion generating mechanismportions of the handheld tool 200, the tool becomes more sturdy androbust for everyday use.

Returning to FIG. 1A, in one embodiment, the voltage commands generatedby TTM 120 drive the actuators, which may be motors that turn theirrespective gear units. In embodiments, the voltage commands/signals turnthe gearing units in a coordinated manner to generate an equal andopposite motion of the attachment arm 104 and the attached implement 102to the direction of detected unintentional high amplitude musclemovements of a user. This cancellation maintains and stabilizes aposition of the implement 102 relative to the housing 106.

One of ordinary skill in the art readily recognizes that a system andmethod in accordance with the present disclosure may utilize variousimplementations of TTM 120 that would be within the spirit and scope ofthe present disclosure. In one embodiment, TTM 120 comprises anelectrical system capable of producing an electrical response fromsensor inputs such as a programmable microcontroller afield-programmable gate array (FPGA), an application specific integratedcircuit (“ASIC”), or otherwise. In one embodiment, TTM 120 comprises an8-bit ATMEGA series programmable microcontroller manufactured by Atmeldue to its overall low-cost, low-power consumption and ability to beutilized in high-volume applications.

One of ordinary skill in the art will readily recognize that anapparatus, a system, or method as described herein may be utilized for avariety of applications. For example, various different implements 102may include user-assistive devices such as a manufacturing tool, asurgical tool, a kitchen utensil (e.g., fork, knife, spoon), a sportingtool, a yard tool, a grooming tool (e.g., comb, nail clippers, tweezers,make-up applicator, etc.), or a dental hygiene tool (e.g., toothbrush,flossing tool, etc.). The different implements may be detachablyattached to the handheld tool 100, or may be integrated therewith. Thus,handheld tool 100 may be useful in not only improving the quality oflife for the multitudes of individuals suffering from neurologicalmotion disorders, but also in assisting in a variety of applicationswhere physiological tremor is an issue including but not limited tomanufacturing, surgical and public safety applications.

FIG. 3 is a functional block diagram illustrating a TTM 300, inaccordance with an embodiment of the disclosure. TTM 300 is one possibleimplementation of TTM 120 illustrated in FIG. 1A, and TTM 220illustrated in FIGS. 2A and 2B. The illustrated embodiment of TTM 300includes an inertial measurement unit (“IMU”) 305, an IMU 307communicably coupled with TTM 300, a controller 310, a memory unit 315,and a communication interface 320.

In one embodiment, IMU 305 is disposed in rigid contact with the housingof a handheld tool to directly measure the tremor motions of the handleand by extension the tremor motions of the user's hand. IMU 307 isdisposed in, or in contact with, an attachment arm of the handheld tooland measures motions of the attachment arm. In one embodiment, IMU 305and IMU 307 have a known orientation relative to one another (e.g.,based on a known orientation of the attachment arm to the handle of thehandheld tool). TTM 300 facilitates the measurement of human tremorsusing IMU 305, and optionally IMU 307, while a user is performing aneveryday task, such as eating or grooming (e.g., applying makeup). Thisis an important distinction over conventional in-clinic evaluations thatsimply measure the tremor of a hand that a patient is attempting to holdsteady. Measurement and tracking of tremors while the patient isperforming an everyday task measures the condition under real-worldscenarios that are most adversely impacted by human tremors.Accordingly, TTM 300 can be embedded within everyday items or tools thatare used routinely by patients to accurately measure and track theircondition. This can lead to improved evaluations.

Not only can TTM 300 of a handheld tool measure and track human tremorsduring a routine task, but it can conveniently do so over a period oftime to obtain a more reliable dataset for statistical analysis.Furthermore, the handheld tool including TTM 300 can be used at homewhere the user is more relaxed and under less stress than a formalevaluation in a practitioner's office. Data collection within the homeenvironment along with larger datasets than can be obtained in-clinic,can provide more reliable data for evaluation of a patient's symptoms.Improved evaluation and diagnosis of the patient's tremors facilitateimproved treatments and interventions of the various diseases and theconditions that cause human tremors.

IMUs 305 and 307 may be implemented using a variety of devices thatmeasure motions of the handle of handheld tool 100, motions of theattachment arm of handheld tool 100, and motions of the handle andattachment arm relative to one another. For example, IMUs 305 and 307may include one or more accelerometers that measure linearaccelerations. In one embodiment, IMUs 305 and 307 includesaccelerometers capable of measuring translational accelerations of thehandle and attachment arm in three orthogonal dimensions (e.g., x, y,and z dimensions). In one embodiment, IMUs 305 and 307 includes agyroscope to measure rotational motions (e.g., angular velocity about anaxis) of the handle and attachment arm of handheld tool 100. In variousembodiments, the gyroscope may be capable of measuring the rotationalmotions about one, two, or three orthogonal rotational axes. In oneembodiment, IMUs 305 and 307 includes a magnetometer to measure motionsof the handle and attachment arm relative to a magnetic field (e.g.,Earth's magnetic field or other externally applied magnetic field). Invarious embodiments, IMUs 305 and 307 may include various combinationsof some or all of the above listed motion measuring devices.Furthermore, these motion sensors may be disposed together in an IMU ona common substrate that is rigidly attached to housing or attachmentarm, or disposed throughout. In one embodiment, by using the combinedmotion measurements of IMU 305 and 307, other motion sensing devices(e.g., contactless position sensors) need not be deployed within ahandheld tool, thereby simplifying the construction of the handheldtool, lowering the cost of the handheld tool, reducing power consumptionby the handheld tool, simplifying motion stabilization control performedby controller 310, etc.

Controller 310 is communicatively coupled to IMUs 305 and 307 and memoryunit 315 to read motion data output from IMUs 305 and 307 and store themotion data into memory unit 315. The motion data is collected over aperiod of time. For example, the motion data may be collected while theuser performs an individual task, over the course of a day, a week, orother period of time. The collected motion data stored in memory unit315 forms a motion log 325. In one embodiment, motion log 325 maycontain enough information about the user's motions (linearaccelerations, rotational velocities, durations of theseaccelerations/velocities, orientation relative to a magnetic field,etc.), based upon the motion data output from IMUs 305 and 307, torecreate those motions using motion log 325. In one embodiment, motionlog 325 may also record date/time stamps of when the motion data wascollected and even include identifiers indicating the type of implement102 that was attached to the handheld tool 100 when the motion data wascollected. The type identifier provides an indication of the activity(e.g., eating with a fork, knife, or spoon, etc.) being performed by theuser when the motion data was collected. This activity information andtime/date stamps may be useful for the practitioner when evaluating thepatient's motion log 325 to determine if the patient's tremors correlateto particular activities or time of day. In yet other embodiments,motion log 325 may also record battery voltage as a function ofdate/time, which may be used to analyzing system performance and batteryusage. Tracking battery voltage is a sort of proxy for the amount ofeffort exerted by actuators 108 and 130 to stabilize implement 102. Assuch, tracking battery voltage or battery consumption correlates to thedegree of a user's tremors since battery consumption will rise withincreased tremors.

In one embodiment, controller 310 further provides signals to actuators108 and 130 for controlling motion of the attachment arm 104 and thusthe implement 102. As discussed herein, the signals generated bycontroller 310 cause actuators 108 and 130 to jointly move theattachment arm 104 and the implement 102 via gearing units 112 and 134in equal and opposite directions as detected user motions of housing106. As discussed herein, the movement of implement 102 occurs throughthe combined/joint movement of attachment arm 104 by actuators 108 and130, providing stabilization for 360 degrees of user movement. That is,based on a known orientation of the housing to the implement, motiondata collected by the IMUs 305 and 307 enables controller 310 togenerate signals that simultaneously drive the first and secondactuators in corresponding first and second degrees of freedom tostabilize the implement during high amplitude motion of the handle of ahandheld tool.

Controller 310 may be implemented with a programmable microcontroller,an FPGA, an ASIC, or other devices capable of executing logicalinstructions. The logical instructions themselves may be hardware logic,software logic (e.g., stored within memory unit 315 or elsewhere), or acombination of both. Memory unit 315 may be implemented using volatileor non-volatile memory (e.g., flash memory).

Communication interface 320 is communicatively coupled to output themotion log 325 from memory unit 315 to remote server 330 via network 335(e.g., the Internet). In one embodiment, communication interface 320 isa wireless communication interface (e.g., Bluetooth, WiFi, etc.). Forexample, communication interface 320 may establish a wireless link to auser's cellular phone which delivers motion log 325 to server 330 via aninstalled tremor tracking application. The application may enable theuser to control privacy settings, add comments about their usage ofhandheld tool 100, setup automatic periodic reporting of motion log 325,initiate a one-time reporting of motion log 325, determine a predominantdirection of unintentional muscle movements detected by TTM 300, receiveinstructions or an indication as to how to set implement 102 relative tohousing 106 to enable motion stabilization in a single degree offreedom, along with other user functions. In yet another embodiment,communication interface 320 may be a wired communication port (e.g., USBport). For example, when the user connects handheld tool 100 to acharging dock to charge power source 122, communication interface 320may also establish a communication session with remote server 330 fordelivery of motion log 325 thereto.

FIG. 4 is a flow chart illustrating a process 400 for trackingunintentional muscle movements of a user while using a handheld tool andperforming high amplitude motion stabilization by the handheld tool, inaccordance with an embodiment of the disclosure. The process 400 isperformed by processing logic that may comprise hardware (circuitry,dedicated logic, etc.), software (such as is run on a general purposecomputer system or a dedicated machine), firmware, or a combination. Inone embodiment, the process is performed by a tremor tracking module ofa handheld tool (e.g., TTM 120 or 220). Furthermore, the order in whichsome or all of the process blocks appear in process 400 should not bedeemed limiting. Rather, one of ordinary skill in the art having thebenefit of the present disclosure will understand that some of theprocess blocks may be executed in a variety of orders not illustrated,or even in parallel.

The process begins by handheld tool detecting manipulation by a userwhile performing an activity (processing block 402). In one embodiment,the user uses the handheld tool (e.g., handheld tool 100 or 200) toperform a task or activity, such as a routine everyday activityincluding eating or grooming. Of course, handheld tool may also be usedfor other non-routine activities, as described above. In one embodiment,handheld tool detects the manipulation by detecting movement of thehandheld tool based on measurements collected from at least one sensorof the handheld tool.

Processing logic tracks user motions with at least two inertialmeasuring units while the user is manipulating the handheld tool(processing block 404). In one embodiment, one of the inertial measuringunits may include the sensor used to detect manipulation of the handheldtool by the user discussed above in processing block 402. In oneembodiment, processing logic detect motion of the handheld tool with theat least two inertial measuring units, and thus movement of a user.Processing logic continues to track user motions while the handheld toolis being manipulated by the user.

Processing logic generates a first motion signal and a second motionsignal that respectively drive a first motion generating mechanism in afirst degree of freedom and a second motion generating mechanism in asecond degree of freedom to stabilize motion of an implement attached tothe handheld tool (processing block 406). As discussed herein, implementmay be attached to an attachment arm of a handheld tool, as discussedabove. In one embodiment, the first degree of freedom and the seconddegree of freedom are different, such as perpendicular to one another.Thus, the combined and simultaneous driving of the motion generatingmechanisms in their respective degrees of freedom enables stabilizationof the implement in 360 degrees of freedom.

The processes explained above are described in terms of computersoftware and hardware. The techniques described may constitutemachine-executable instructions embodied within a tangible ornon-transitory machine (e.g., computer) readable storage medium, thatwhen executed by a machine will cause the machine to perform theoperations described. Additionally, the processes may be embodied withinhardware, such as an application specific integrated circuit (“ASIC”) orotherwise.

A tangible machine-readable storage medium includes any mechanism thatprovides (i.e., stores) information in a non-transitory form accessibleby a machine (e.g., a computer, network device, personal digitalassistant, manufacturing tool, any device with a set of one or moreprocessors, etc.). For example, a machine-readable storage mediumincludes recordable/non-recordable media (e.g., read only memory (ROM),random access memory (RAM), magnetic disk storage media, optical storagemedia, flash memory devices, etc.).

The above description of illustrated embodiments of the invention,including what is described in the Abstract, is not intended to beexhaustive or to limit the invention to the precise forms disclosed.While specific embodiments of, and examples for, the invention aredescribed herein for illustrative purposes, various modifications arepossible within the scope of the invention, as those skilled in therelevant art will recognize.

These modifications can be made to the invention in light of the abovedetailed description. The terms used in the following claims should notbe construed to limit the invention to the specific embodimentsdisclosed in the specification. Rather, the scope of the invention is tobe determined entirely by the following claims, which are to beconstrued in accordance with established doctrines of claiminterpretation.

What is claimed is:
 1. A method performed by a handheld tool, the methodcomprising: detecting motion of a housing of the handheld tool whenmanipulated by a user while the user is performing a task with auser-assistive device attached to an attachment arm of the handheldtool, wherein the housing forms a handle that is grasped by the userwhile the user is performing the task with the handheld tool; storingthe detected motion in a memory of the handheld tool as motion data; andcontrolling, by a processing logic based on the motion data, a firstmotion generating mechanism and a second motion generating mechanism bygenerating a first motion signal and a second motion signal thatrespectively drive the first motion generating mechanism in a firstdegree of freedom and the second motion generating mechanism in a seconddegree of freedom to stabilize motion of the user-assistive deviceattached to the attachment arm of the handheld tool, wherein the firstmotion generating mechanism is rigidly mounted to and in line with theattachment arm and the second motion generating mechanism is rigidlymounted to the housing, and wherein the attachment arm is coupled withthe housing via a coupling of the first motion generating mechanism withthe second motion generating mechanism.
 2. The method of claim 1,wherein the first motion generating mechanism moves the attachment armin the first degree of freedom and the second motion generatingmechanism moves the attachment arm in the second degree of freedom tostabilize motion of the user-assistive device in 360 degrees of freedomas a result of high amplitude motion of the housing, wherein the highamplitude motion comprises user tremor motions having a range of atleast 2 centimeters.
 3. The method of claim 2, wherein the first motiongenerating mechanism moves the attachment arm in the first degree offreedom in a first range up to 10 centimeters and the second motiongenerating mechanism moves the attachment arm along with the firstmotion generating mechanism in the second degree of freedom in a secondrange up to 10 centimeters.
 4. The method of claim 1, wherein a flexiblesleeve is attached to the housing and the attachment arm, wherein theflexible sleeve seals a portion of the handheld tool between the housingand the attachment arm, and wherein the portion contains the firstmotion generating mechanism and the second motion generating mechanism.5. A non-transitory machine readable storage medium having instructionsstored thereon, which when executed by a processing system of a handheldtool, cause the handheld tool to perform a method comprising: detectingmotion of a housing of the handheld tool when manipulated by a userwhile the user is performing a task with a user-assistive deviceattached to an attachment arm of the handheld tool, wherein the housingforms a handle that is grasped by the user while the user is performingthe task with the handheld tool; storing the detected motion in a memoryof the handheld tool as motion data; and controlling, by the processingsystem based on the motion data, a first motion generating mechanism anda second motion generating mechanism by generating a first motion signaland a second motion signal that respectively drive the first motiongenerating mechanism in a first degree of freedom and the second motiongenerating mechanism in a second degree of freedom to stabilize motionof the user-assistive device attached to the attachment arm of thehandheld tool, wherein the first motion generating mechanism is rigidlymounted to and in line with the attachment arm and the second motiongenerating mechanism is oriented parallel and in line with the housing,and wherein the attachment arm is coupled with the housing via acoupling of the first motion generating mechanism with the second motiongenerating mechanism.
 6. The non-transitory machine readable storagemedium of claim 5, wherein the first motion generating mechanism movesthe attachment arm in the first degree of freedom and the second motiongenerating mechanism moves the attachment arm in the second degree offreedom to stabilize motion of the user-assistive device in 360 degreesof freedom as a result of high amplitude motion of the housing, whereinthe high amplitude motion comprises user tremor motions having a rangeof at least 2 centimeters.
 7. The method of claim 1, wherein the firstmotion generating mechanism is coupled to the second motion generatingmechanism through first and second pivots.
 8. The method of claim 7,wherein outputs of the first and second motion generating mechanismsface toward each other with the first and second pivots disposedtherebetween.
 9. The method of claim 1, wherein the second motiongenerating mechanism is disposed within the housing forming the handlewhere the user grasps the handheld tool while performing the task. 10.The method of claim 1, wherein detecting motion of the housing of thehandheld tool when manipulated by the user comprises: detecting themotion with a motion sensor disposed in or on the housing that forms thehandle.